Reduced patient restrictions following total hip arthroplasty: study protocol for a randomized controlled trial.

Background: Total hip arthroplasty (THA) is a very common procedure in orthopedic surgery. In the Netherlands, 25,642 primary THAs were performed in 2013. Postoperative hip dislocation is one of the major complications and has been reported in 0.5 to 10.6 % of patients after primary THA. Several reports regarding the use of an anterolateral surgical approach have shown that a non-restriction or reduced restriction protocol does not increase the dislocation rate. For the posterolateral surgical approach it has been suggested that patient restrictions might be unnecessary but the amount of available literature is scarce. As such, randomized controlled trials aimed at investigating restrictions following THA using a posterior approach are strongly recommended. The aim of this prospective randomized controlled trial is to investigate the non-inferiority hypothesis concerning the early dislocation rate after THA in patients with and without the use of a reduced restriction protocol.

Methods/design: After providing informed consent a group of 456 patients with symptomatic coxarthrosis will be randomized to receive a THA either with care as usual, i.e. receiving postoperative restrictions including the advice to sleep in a supine position for the first 8 weeks postoperatively, or reduced restrictions with no recommendations regarding the position during sleeping. Primary outcome measure will be the percentage of early dislocations within the first 8 weeks after THA. Secondary outcome measures will be patient satisfaction, time to functional recovery, quality of sleep and patient's self-reported compliance with postoperative instructions.

Discussion: To our knowledge this will be the first randomized controlled trial that compares a reduced restriction protocol with a restricted protocol following THA using a posterolateral surgical approach. Our hypothesis is that a reduced restriction protocol following THA with use of a posterolateral surgical approach has no influence on the early dislocation rate compared to a restricted protocol. Instead, embracing a reduced restriction protocol might even contribute to a higher quality of sleep, thereby facilitating a faster uptake and return to daily functions in patients after THA.

Trial Registration: ClinicalTrials.gov NCT02107248 , registration date 3 April 2014.